Sound producer



C. C. FARMER SOUND PRODUCER Feb. 4, .1930.

Filed Dec. 18. 1928 ENVENTOR CI 'YDE C. FARM-IR ATTORNEY r QLYIDE QFAR-M R, or 'PITErsBURGH,PE NSY A I 3 ing horn 6."

v Pat entedFeb. 4, 1930:.

SI NQR To THE 'WE 'TIKG- HOUSE AIR BRAKE o v r OEW M l G PENNSYLVANIA; A comm ssion rENNsvLvANIA soimn rnopvcEfgs Application filed December-i8, 1928; {SeriaL'Nc 326,733.

l This invention relates to audible'signal devices and more particularly to'pneumatically operated sound producers. V An object of the inventionListoprovide a sound producer in which means are provided forclosingthe mouth of the horn when the deviceissilent'. g

Another object of the'invention is to pro- 7 V, "vide'a sound producing device with a closure I I '10 for the mouth-of the horn ofthe device, which closure is automaticallyopened and closed by mechanism actuated by the sound producing means. V

' Another ob'ect of th'einvention is toprovide a soundjproducerof the character mentioned whichis relatively simple in construc5 tion, and reliableand exact in function under all conditions ofservicep The invention alsocomprises certain'jnew' anduseful improvementsin the construction,

arrangement and 'combinationof the several parts of which it is composed, as will be hereinafter'more-fully described and claimed.

Inthe accompanying drawings: Figure 1 is a side elevatiom' partlyin section, of a sound producingapparatus embodying the inventiomthe closure for the. mouth of the horn being shown closed; Fig. 2 is a front a view; F'g. 3 is apl an of the forward portion .9. of the structure shown in -Fig. 1 ;.and' Fig. 4

is a view similar to 3,showing the closure openu'y h r I V Referring to thedrawing, the soundpro- V ducing apparatus may comprise a casingil 357 having-a chamber-2 which is open to a flexible" diaphragm mounted fin the'end-vof; the

' The cas ng 1 is provided with 'a ithreaded I opening at the side opposite thedi'aphragm3 into which, is-screwed a resonance tube, 14.

Thistubezha's anenlarged porti0n-5 forming a shoulder adapted to; engage" the end face of thethreaded' portion ofthe casing 1. Secured to the tube' is a suitableamplify- When the tube dis screwed downso that the'shoulderthereoi engagesthe end "of the thre'aded portion-of; the'easing, the free end ofthe'tubejust engages the diaphragm 3.

" Secured tofthe centralafportion of the diadiaphragm Sremains at scribed;

' phr agm and extending intothe open end of the tube 4 is 'a weight 7 Spacedfrom, and enclosing the side of the; diaphragm-3 oppositeto the weight 7, is a cover plate :8pro'vided with an opening?) so that" the chamber atthe' outer face ofthe" atmospheric pressure at all times.

The chamber 2' is'connected by a restricted opening 10 to a conduit or passage 12 leadingto a cylinder ll." i

Contained in the cylinder 11 is apiston 13,

sure ina chamber 15. v. The" spring side of the piston 13 is} pro,-

which is subject on one side tothe pressure A l of an e -pansible spring 14, and which is .Sl lbJGCfibIlfilhG other'si'de to fluid un'derpres videdwith a stein16 which is slidab'ly mount? ed in al'tubu'lar boss 17- projecting-inwardlyfrom the end wall: of the'cylinder 11.

The projectingfend of the boss 17 is formed with a seat ring 18 "against which the seat 19: of the-piston 13'engages, when the piston is moved outwardly in the manner to be de- The c'h'amber'15v connected to api-pe E205 through-which fluid" under pressure is supplied to said chamber, the amount "of fluid means of the plug valve 30of-an angle cook 21. Theipistonfstemilfi proj ect-s'beyond the end ofcy1inder11-and its projecting end carries 7 V a crosshead" to. which are; connected the. "inner: ends of a pairot Links; 23.;

1 The forward end ofthel i ks 23 are-pi o ally co nect t 2 to he m 2 w ir i shutters 26 m un d on h fla ing mouth f- 1. 51 6 by t le ing s.

c-AS S own,- t e sh t e s- .2 may ons t f two semi-circularlplates, which arefadapte d flowin'glthrough the pipe being controlledibyi 1 I 0. o lthem luth-of he Qrn when .the lei-j v e, is. inoperat v 'Qr, ilent w o pr e othe foreign matter into 'thef'horn', which Ordinarily a e fi ndency 0 render h f sound producingelements inoperative.

the entrance ofisnow'and ice; water, dirt, and

I In operati on,"whenthe plugvalve 30 I is turned to'qconnect the waterway or porter with the'pipepassagqfiuid under pressure will he supplied to -theschamber building ing the mouth of the horn 6. Such shutters will remain in open position as long'as the piston 13 is seated against the seat ring 18 by the pressure of the fluid in Chamber 15.

When the piston 13 isseated against the seat ring 18, port 33 will be uncovered and the fluid supplied to chamber 15 flows through the conduit 12 and the restricted opening 10 into chamber 2, and the ressure of fluid in chamber 2 builds up so tiat the diaphragm 3 is moved outwardly.

:In moving out, communication is opened from chamber 2 to the space within the tube.

' 4. The pressure in said chamber is then quickly reduced, since the rate of flow through restricted port 10 is considerably less thanthe rate of flow from chamber 2'to tube 4:. The pressure on the diaphragm 3 being thus relieved, said diaphragm returns to its position engaging the end of the tube 4. The openingmovement is then repeated. Thediaphragm 3 is thus caused to vibrate and thereby produces a sound which is amplified by the usual operation of the horn 6. The addition of the weighted member 7 to the diaphragm 3 makes it necessary for the fluid pressure to be built up to a higher point before the diaphragm will move fromengagement with the end of the tube 4:, than would be the case with an unweighted diaphragm,

but when the diaphragm does move, the higher pressure causes a greater movement of the diaphragm and consequently, a greater amount of potential energy is stored up, so that the return movement of the diaphragm is efiected more forcibly. A'-more positive 0 enin and closin movement of the dia z: a: V

phragm is thus assured. I 7

An opening 34 is formed through the piston 13, and chamber 35 on the spring side of the piston is open to atmospheric pressure through a leakage groove 36. I

' When the plug valve 30'is operated'to shut off the supply of fluid-to the chamber 15, the spring 14 returns the piston 13 to its normal position, as shown in Fig. 1, and this, action will close the shutters 26, as will be readily understood. The opening 34 insures that the piston 13 will return to, its normal position.

However, said opening enables the piston to release slow enough to permit the shutter to remain open for a short time, as occurs when a series of short blasts are to be produced by the sound producing apparatus.

While one illustrative embodiment of the invention has been described inv detail, it is not my intention to limit its scope to that em bodiment or otherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A device of the class described comprising sound producing means, a horn, movable closureelements for closing the horn when the soundproducing means are inoperative, and means actuated by the sound producing means for actuating the closure elements.

2. A pneumatically operated sound producer having a horn provided with a pivoted shutter for closing the horn when the sound producer is inoperative, means for supplying fluid under pressure to the sound producer, and fluid pressure sensitive means for actuat ing the shutter when the fluid is being. supplied to the sound producer. 7

3. A device of the class described compris- -ing fluid operated sound producing means having a horn provided with shutters which normally close the mouth of the horn, a cylinder containing a piston, links connecting the piston and the shutters, said vcylinder being in communication with the sound producing means when the piston is-at one end of its stroke, and means for supplying fluid under pressure to the cylinder to cause the piston to move to the position in which'fluidwill be supplied to the sound-producing means.

' 4.. The combination with a sound producing means operated by fluid under pressure and a horn associated therewith, of means normally closing the horn outlet and operated to open the horn outlet upon supplying fluid under pressure to said sound'producing means. j c

5. The combination with a sound producing means operated by fluid under pressure and a horn associated therewith, of a shutter for controlling the outlet of the horn, and means operated by fluid under pressure for operating said shutter, V

6. The combination with a soundproducing means operated by fluid under pressure and a horn associated therewith, of a shutter for controlling the outlet of the horn, and means operated by fluid under pressure for operating said shutter and for controlling communication through which fluid under pressure is supplied to said sound producing means.

7. A device of the class described comprising sound producing means having a horn provided with fluid operated means'for closing the horn when the device is inactive. I

8 The combination with sound producing means and a horn associated therewith, of fluid operated means for closing the horn outlet when the sound producing means is inactive. I v

In testimony whereof I have hereunto set my hand, this 17th day of December, 1928.

, CLYDE C. FARMER. 

